This invention relates to air-handling systems and in particular to sealing air-handling systems to prevent air from inadvertently escaping from them.
There are many spaces, such as hospitals and manufacturing clean rooms, where air entering the space must be strictly controlled to prevent contaminants from entering the space. This is accomplished by circulating the air in the space through air-handling systems having filters through which all of the air entering the space must pass. A common problem with these air handling systems is leakage of unfiltered air into the space at the intersection of components of the air-handling system. Hopkins, et al., U.S. Pat. No. 6,351,920 describes an apparatus for providing a seal around the perimeter of ceiling mounted modules to prevent air from by-passing the modules. This is accomplished by inserting blades which project from the periphery of the module into a sealant in troughs located in the ceiling grid elements.
In air-handling systems of this type air often is distributed through sheet metal plenums and in some applications air must be shared between side-by-side plenums. This is accomplished by forming an air passageway in the adjacent walls of the plenums. Heretofore these passageways have been sealed to prevent air from escaping between the plenums by placing a flexible U-shaped trim piece over the exposed ends of the plenum walls around the periphery of the passageway and placing a caulking compound around the perimeter of the trim piece, or by placing a caulking compound directly over the exposed ends of the plenum walls. This procedure is labor intensive and if the caulk is not applied correctly, leaks can occur.